There have been unfounded allegations that the WEC violated the law by not removing approximately 232,000 voters from the registration list because they may have moved.
The Wisconsin Supreme Court ruled in April 2021 that Wisconsin law did not direct the Wisconsin Elections Commission to not remove voters from the registration list on the basis of a possible move. Instead, statutes reserved that authority for local officials and the city, village, or town level. The full text of the decision is available here: https://elections.wi.gov/sites/elections/files/2021-04/Supreme%20Court%20Decision%20Zignego%20v%20WEC.pdf
The current process requires anyone who may have moved to affirm their address when receiving a ballot. These voters have a watermark next to their name in the poll book and were asked to sign to affirm that they still live there. Any voters who have moved were directed to register to vote, and provide proof of residence, before they can be issued a ballot.